The Network Logical Data Manager (NLDM) Release 2 program product collects and correlates data about sessions and provides users with online access to the collected data. It allows a user at a central control point to examine information related to specific sessions and to identify network problems.
NLDM may be used in several ways, depending on the needs of a particular system or installation.
You may start NLDM either before or after the network is activated. To use NLDM to help identify the first occurrence of a problem, NLDM should be running all the time.
To use NLDM to help identify a subsequent occurrence of a problem, be sure that NLDM is initialized and that the network is activated. Then, begin traces of sessions involving the resources with which there is a problem.
NLDM collects data about same-domain, cross-domain, and cross-network sessions and maintains the collected session data on a session basis.
Session awareness and routing data may involve non-SNA terminals supported by the IBM program product, Network Terminal Option (NTO), which appear to the host to be SNA devices. In addition, NLDM collects data relating to the data flows for BSC 3270 devices. Collecting data for cross-domain sessions requires NLDM in both domains. Collecting data for cross-network sessions requires NLDM in each network.
NLDM collects session data from VTAM and from NCP. The session data includes information about the session partners, session activation and deactivation, the physical configuration associated with the session, access method PIU data, and network control program (NCP) data.
NLDM collects response time data that has been measured by the Response Time Monitor (RTM) feature of a 3274. This data is measured within response time ranges specified by the customer.
NLDM runs as an application program under the Network Communications Control Facility (NCCF). Access to NLDM can be controlled by using security functions provided by NCCF. NLDM can coexist with the Network Problem Determination Application (NPDA) program product and with the IBM Threshold Analysis and Remote Access feature.
NLDM uses system functions provided by NCCF to communicate with the SNA access method and with the Virtual Storage Access Method (VSAM) data base in which the collected session data is stored. For more
information about NCCF functions, refer to the section about NCCF.
2-42 VTAM General Information
Figure 2-13 on page 2-44 lists NLDM functions in Releases 1 and 2. Use the table as follows:
• Under "Type of Network" on the left, an "X" under the "8" column tells you that the function can be used in a single-domain network; under
"M" it can be used in a multiple-domain network; and under "I" with interconnected networks.
• Descriptions of the functions appear after the table in the same order.
• Under "Release" on the right, an "X" appears under the release of NLDM that has the function.
If you are migrating from NLDM Release 1, the first new function is
"Initialization (with interconnected networks)." Under "Release" there is no "X" for "Release 1"; thus, the function is new to your installation and you may want to read about it in the description following the table.
Type of Release Effected In Network
Function
Release 1 Release 2
S M I
'x X No interconnected networks X X
Initialization
X I nterconnected networks X
X X Collect No interconnected networks X X
session
X data Interconnected networks X
X X Put data in No i ntercon nected networ ks X X
the data
X base I nterconnected networks X
X X Start or stop No interconnected networks X X
collection of
X session awareness Interconnected networks X
data
X X Activate or No interconnected networks X X
deactivate
X session traces I ntercon nected networ ks X
X X Display No interconnected networks X X
session
X data Interconnected networks X
X X Test No interconnected networks X X
session
X connectivity I nterconnected networks X
X X X Collect reponse time data X
X X X Display response time data X
X X X Display N LDM help information X X
X X X Display the port address of a station X
X X X Display and change program function key settings X
Note: These functions are described below.
Figure 2-13. Functions in NLDM Releases 1 and 2
Initialization: NLDM is initialized whenever NCCF is initialized. During initialization the NLDM start-up parameters specified by the customer in an NCCF parameter definition data set are processed. One parameter which may be specified is the option to begin the collection of session awareness data at initialization. These start-up parameters provide the customer with the ability to use NLDM based on individual needs. For additional information about requests that may be included in the
parameter definition data set, refer to the NLDM Installation and Operation manual.
2-44 VTAM General Information
,-Collect Session Data: NLDM collects data about SNA sessions involving logical units (LUs), physical units (PUs), or system services control points (SSCPs). SNA sessions for which NLDM can collect data are LU-LU, SSCP-LU, SSCP-PU, and SSCP-SSCP.
NLDM can collect two types of data about a session: (1) session awareness data and (2) session trace data.
• Session awareness data is collected for all active sessions. It includes:
The session type
The names of the session partners The session activation status
Information about session and route configuration:
Addresses and names of subareas on the explicit route assigned to the session
Transmission group numbers
Addresses or names of SSCPs that own links in the transmission groups.
For more information see "Session Awareness Data".
• Session trace data is collected only for sessions involving a resource for which a session trace has been started. It consists of:
Session activation parameters
Access method path information unit (PIU) data NCP data.
For more information, see "Session Awareness Data" on page 2-48.
NLDM can collect response time data from a 3274 controller with the response time monitor feature. Response time is measured by the 3274 for each SNA transaction associated with it. NLDM collects response time only from each 3274 for which collection has been started. For more information see "Response Time Data".
Put Data in the Data Base: NLDM stores collected session data in a VSAM data base. The user specifies the name and size of the data base during the installation of NLDM. Session data associated with an active session is kept in main storage. When the session ends, the session data is copied from main storage into the VSAM data base. The user may also request that the data be transferred from main storage to the data base while the session is still active.
Session awareness data (including session termination notifications) is provided and kept by each VT AM that owns at least one session partner or is the gateway VTAM for a cross-network session.
Figure 2-14 on page 2-46 shows the types of resources for which NLDM can collect. session data.
Session Trace Data Session
Awareness PIU Data and NCP
Resource Data Session Data
Activation Parameters
Channel-attached SNA terminals X X
Channel-attached non-SNA terminals X X
NCP-attached SNA terminals X X
(includes SSC 3270 terminals)
NTO terminals (including SSC and X X
start-stop terminals other than 3270s)
Host LUs associated with user X X
application programs
Host SSCP X X
NCP (PU Type 2) X X
Figure 2-14. Resources that Can Have Sessions Traced
Start or Stop Collection of Session Awareness Data: The user can start or stop the collection of session awareness data. When the collection of session awareness data is started, NLDM receives information about active sessions as well as about sessions subsequently started. NLDM collects session awareness data from each VTAM (Version 2 Release 2) that owns a session partner or that acts as a gateway VT AM in setting up a cross-network session.
The initiation of session awareness notifications from VT AM may begin upon initialization of NLDM or be deferred until the ENABLE command is issued. With this enhancement NLDM collects session awareness data for existing as well as subsequently started sessions. The user may stop the collection of session awareness data by use of the DISABLE command.
Activate or Deactivate Session Traces: NLDM begins collecting session trace data only after a session trace is started. Session traces may be started during or after NLDM initialization. Session traces are started at NLDM initialization for resources specified in the NCCF parameter definition data set; resources that can be specified in that data set are all L U s, all SSCPs, or both.
Once NLDM is initialized and enabled, the user may start or stop session traces for specific network resources, or all network resources. In a
multiple-domain network, a user in one domain may start a session trace for a resource in another domain if NLDM has been initialized in that domain.
Session trace data is collected for a session involving two resources in the same domain when a session trace is started for either session partner. In a multiple-domain network, all session trace data for a cross-domain session is collected only when session traces are started in both domains.
2-46 VTAM General Information
X
X
Activation of response time data collection: At initialization of NLDM, the customer defines performance classes, each with its own:
• Response time ranges for measuring response time
• Response time definition
• Response time objective (such as 80% of transactions should take under 5 seconds).
After defining performance classes, the customer maps sessions into performance classes.
Based on the initialization information, the RTM feature of the 3274 begins to measure response times and stores the information for collection by NLDM. The user collects response time data from the 3274 by either invoking an explicit collect command, or by defining an NCCF command list.
Display Session Data: The user can display the collected session data using a set of panels organized in a hierarchy. If the user wants to display information about an active session, NLDM retrieves the session data from main storage. If the user wants to display information about a previously active session, NLDM gets the session data from the VSAM data base.
NLDM provides cross-domain support to allow you to view session data where one session partner resides in another domain. You may also view session data where both partners reside in a different domain from the one containing your terminal. A user can view data involving a session partner in another network, although he may be denied access to specific session configuration information about cross-network sessions.
Session awareness data is displayed in the following ways:
• SN A resource lists
• A list of the most recent sessions for a resource
• Domain lists
• Session configuration
• Explicit route configuration
• Transmission group information.
Session trace data is displayed in the following ways:
• Session activation parameters
• Access method PlU data
• NCP data.
Response time data is displayed in the following ways:
• Response time summaries
• Response time trends
• Response time for a session by collection period.
Test Session Connectivity: The user can test the session connectivity for any active session. NLDM requests the access method to issue an ER test to check the physical path for a particular session. For a cross-network session, NLDM requests the adjacent NLDM to request an ER test in its network. If several networks are involved, each NLDM requests the NLDM in the adjacent network to request its access method to issue an ER test for that network. In an interconnected network environment this would be very difficult to accomplish without NLDM. The VTAM route test can test the route into an adjacent network. If more than two networks are
involved, VTAM route testing is limited. NLDM allows the entire route to be tested with only one command.
As a result of initiating a session connectivity test an appropriate NLDM message will be issued indicating the results. If the test fails, the failing network, domain, and subarea are identified.
Display NLDM Help Information: The NLDM user can, display a set of panels describing NLDM commands. The user may also display what session traces are active and what the keep settings currently are. The keep settings are the user-specified number of PIUs kept while tracing, and the number of historical sessions kept on the VSAM data base.
Display the Port Address of a Station: The user can issue a command to verify the NCP line port address associated with a station attached to an NCP within the domain of the NLDM.
Display and Changing Program Function Key Settings: The NLDM user can display or change the program function (PF) key settings for NLDM commands.